Field of the Invention
The present invention relates to a substrate including a thin film transistor and a display panel having the same, and more particularly, to a substrate including a thin film transistor, which may prevent light leakage without a reduction in an aperture ratio, and to a display panel having the same.
Discussion of the Related Art
An image display, which displays various information on a screen, is a core technology of the information communication era and is being developed to achieve thinner, lighter, more portable and better-performing products. Accordingly, flat panel displays, which may overcome the disadvantage of the weight and volume of cathode ray tubes (CRT), are in the spotlight.
Among flat panel displays, a liquid crystal display displays an image by adjusting the light transmittance of liquid crystals via an electric field, which is formed between a common electrode and a pixel electrode connected to a thin film transistor. The liquid crystal display is formed such that a substrate including a color filter and a substrate including a thin film transistor are bonded to each other with a liquid crystal layer interposed therebetween. At this time, a column spacer is formed between the thin film transistor substrate and the color filter substrate in order to maintain a cell gap.
When pressure is applied from outside the liquid crystal display, the column spacer is moved by the pressure. The movement of the column spacer causes damage to an alignment film, which is in contact with the column spacer. Because the damaged alignment film cannot align liquid crystals in a desired direction, light leakage occurs in the damaged region of the alignment film, which is problematic. In particular, when the substrate is reduced in thickness to achieve a thinner liquid crystal display, the substrate having a reduced thickness is easily deformed even by small pressure, whereby light leakage from the thin liquid crystal display is increased somewhat. Although the line width of a black matrix around the column spacer may be increased in order to solve this light leakage problem, this decreases an aperture ratio.